Knock box



FIG. 1 is a front view of the knock box;

FIG. 2 is a back view of the knock box;

FIG. 3 is a left side view of the knock box; the right side view is a mirror image of the left side view;

FIG. 4 is a top view of the knock box;

FIG. 5 is a bottom view of the knock box; and,

FIG. 6 is a perspective view of the knock box.

The broken lines indicate the bounds of the claimed design and form no part of the claimed design. 

CLAIM We claim the ornamental design for a knock box, as shown and described. 